Double spherical dressing apparatus

ABSTRACT

Double spherical dressing apparatus for grindstone includes cutting table slidably mounted at right angles to axis of rotation of grindstone. Swing shaft is journaled within main assembly and assembly is attached to cutting table for sliding motion along path parallel to the axis of grindstone. Swing table is connected to rotate with and relative to swing shaft. Shaft table carries dresser tool and tool rotates about axis of swing shaft and swing table to dress peripheral faces of grindstone.

United States Patent Kikuchl 1 May 16, 1972 [54] DOUBLE SPHERICAL DRESSING Referenm Cited APPARATUS UNITED STATES PATENTS Inventor: Makolo Kikuchi, him h J p 2,922,413 1/1960 Schultze ..125/ 11 [73] Assignee: Toyoda Koki Kabushiki K i h ,093,128 6/1963 Serdel ..l25/l l Asahlmachl Japan Primary Examiner-Harold D. Whitehead [22] Filed: Apr. 1, 1970 Attorney-Connolly and Hutz Double spherical dressing apparatus for grindstone includes 7 [30] Forelgn Apphcauon Priority Dam cutting table Slidably mounted at right angles to axis of rota- Apr. 7, 1969 Japan ..44/26779 of grindsmne- Swing Shaft is J'Oumaled Within min g sembly and assembly is attached to cutting table for sliding [52] U.S.Cl ..l25/l1 motion along P Parallel t the axis of grindstone' Swing [51] um CI "324!) 53/06 table is connected to rotate with and relative to swing Shaft. Field of Search 125/11 Shaft able and axis swing shaft and Swing table to dress peripheral faces of grindstone.

5 Claims, 6 Drawing Figures DOUBLE SPHERICAL DRESSING APPARATUS 7 BACKGROUND OF THE INVENTION The present invention relates to a dressing apparatus, and more particularly to a double spherical dressing apparatus for operating upon the peripheral arcuate faces of a grindstone.

In an apparatus for dressing grindstones having arcuate peripheral faces with different centers, the swinging arm that carries the diamond dresser rotates around a vertical axis so that the dresser moves in ahorizontal plane that contains the axis of rotation of the grindstone and the dresser tip. In view of the close intervals between grindstones on a spindle wheel it is impossible to provide a plurality of swinging arms to match the peripheral faces of the grindstone being dressed because these arms would interfere with one another. Also, there is the inconvenience that at midpoint between a pair of adjacent peripheral faces, the diamond dresser axis is inclined and tends to interfere with the opposite grindstone face.

Accordingly, it is an object of the present invention to provide a double spherical dressingapparatus which functions in a highly satisfactory and efficient manner to operate upon the arcuate peripheral faces of a grindstone.

SUMMARY OF THE INVENTION the framework for movement normal to the axis of rotation of the grindstone. A motivating device is provided for moving the cutting table relative to the grindstone. A main assembly is slidably mounted on the cutting table for movement parallel to the axis of rotation of the grindstone, and a swing shaft is rotatably mounted within the main assembly. A first driving device is provided for rotating the swing shaft. A swing table is pivotally mounted to the swing shaft while a downwardly extending arm is slidably mounted on the swing table for movement normal to the axis of rotation of the grindstone. The arm carries a grindstone dressing tool. Also, a second driving device is provided for rotating the swing table so that the dressing tool may be selectively swung about each of the axes of the swing shaft and the swing table when the first and second driving devices are operated. The axis of the dressing tool and the axis of rotation of the grindstone are at right angles to one another when the tool is midway between the two circular peripheral faces of the grindstone being dressed.

BRIEF DESCRIPTION OF THE DRAWING Novel features and advantages of the present invention in addition to those mentioned above will become apparent to those skilled in the art from a reading of the following detailed description in conjunction with the accompanying drawing wherein: Y FIG. 1 is a top plan view of an embodiment according to the present invention;

FIG. 2 is a sectional view taken along line 22 of FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 1;

FIG. 5 illustrates the relationship between the grindstone and the diamond dresser of the apparatus according to the present invention; and

FIG. 6 illustrates another dressing according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION operated upon by the apparatus. A cutting table 2 is slidably mounted to the stand 1 at the channel la.

An internally threaded sleeve 3 is fastened by bolts 4 to an opening at the rear of the cutting table 2. A feed screw 5 is in mating engagement with the sleeve 3. A step 5a is provided on the rear end portion of the feed screw and a feed wheel 7 is connected to the outer free end of the screw. The feed wheel 7 and step 5a are located on opposite sides of a rigid support member 6 so that manipulation of the wheel 7 only causes the feed screw 5 to rotate which in turn causes cutting table 2 to slide along the channel la. y

A main assembly 8 is slidably mounted to the table 2 by a dovetail connection 8a in such a manner that the main assembly 8 slides along a path parallel to the axis of the grindstone 54. A feed shaft 10 is provided for shifting the main assembly 8 relative to the cutting table 2. The feed shaft 10 is integrated with a feed screw 11. Stops 11a and 11b on the feed screw 11 cooperate with a support member 12 so that rotation of the feed screw 1 1 only enables the screw to rotate which in turn causes the main assembly 8 to shift laterally relative to the table 2. v

A vertically disposed opening 8b is provided in the main assembly 8. A shaft 13 is journaled inside the opening 8b by bearings 14, 15. One end of the shaft 13 has a threaded portion 13a upon which are located an internally threaded nut 17 and washer 16. A collar 18 loosely surrounds the threaded portion 13a and a bearing member 19 secured to the main assembly 8 is located around the collar. This arrangement fixes the outer race of the upper bearing 14. A similar bearing 20 is located at the lower open end of the vertical bore 8b for holding the outer race of the lower bearing 15.

A swing table 13b is integrated with the swing shaft 13. The table 13b has a gear segment 21 with a pinion 210 formed on its arc edge. A rack 22 with teeth 22a meshes with the pinion 21a and is connected to a piston 24 slidablyfitted within a cylinder 23 secured to the main assembly 8. The cylinder 23 is connected to a hydraulic pressure source via a throttle valve and a solenoid valve (not shown). The piston 24 has a dog 24a to adjust the throw of the rack bar 22.

As shown best in FIG. 3, a member 50 is secured to the swing table 13b for movement therewith. The member 50 has a bolt C threadably fitted to an interiorly threaded bore on the member 50. A stop D in line with the bolt C is secured to the main assembly 8. The bolt C is adjusted relative to the member 50 so that it hits the stop D when the dresser 43, described more fully below, leaves the right extreme of the grindstone.

A dovetail groove sliding part is located parallel to the axis of the grindstone 54. A circular table 25 with a dovetail groove sliding portion 25a formed thereon fits the sliding part 13c so that the table 25 slides along a path parallel to the axis of rotation of the grindstone. The sliding table 25 has a feed shaft 27 for effecting the movement of the table 25 relative to the main assembly 8. Steps 28a and a support member 13d fitted to the table 13b enable relative movement between the table 13b and the table 25 when the feed screw 28 is rotated by manipulating the feed shaft 27.

A circular recess 25b is located on the underside of the table 25. The recess is defined in part by a guide surface 250. A circular body 29 having a guide surface 290 is swingably fitted into the recess 250. A swing plate 30 is rigidly fixed to the bottom of the swinging table 25. A guide surface 30a formed on the plate 30 mates with the guide surface 29a on the body 29. As shown best in FIG. 1, the axis of the shaft 13 as well as the axis of the swing body 29 are parallel to one another and equally displaced from the axis of rotation of the grindstone 54.

As shown best in FIG. 3, a projection 29b is formed on the underside of the body 29. A table 31 is secured by bolts 32 to the underside of the body 29 so that a projection 29b on the body 29 mates with a recess 31b in the swing table 31. A swing plate 33 has a guide surface 33a formed thereon so that it matches the guide surface 25: of the table 25. Bolts 34 hold plate 33 in place. Ball bearings 35 are provided as shown best in FIGS. 3 and 4.

The table 31 has a gear segment 46 with a pinion 46a formed on its outer arc edge. A rack bar 47 with rack teeth 47a meshes with the pinion 46a and is connected to a piston 49 slidably mounted within a cylinder 48 which in turn is secured to the table 25. The cylinder 48 is suitably connected to a hydraulic pressure source via a throttle valve and solenoid valve (not shown). The piston 49 has a dog 49a to adjust the throw of the rack bar 47.

As shown in FIG. 2 the table 31 has a member 51 which supports a threaded stop bolt A. A stop plate B in line with the bolt A is secured to the table 25. The stop bolt A is adjusted so that it hits the stop B when the dresser 43 swings to midposition after dressing the grindstone periphery from the left, as described more fully below.

As shown best in FIG. 4 a dovetail groove is formed on the underside of the table 31. The groove is at right angles to the axis of the grindstone 54. A swing member 36 having a vertical arm 52 and a dovetail groove sliding part 36a is slidably mounted relative to the table 31. The arm 52 is perpendicular to a horizontal plane which embraces the axis of the grindstone 54 as well as the tip of the dresser 43. The swing member 36 has a feed shaft 37 for causing member 36 to slide relative to the table 31. Movement of the member 36 adjusts the swing radius of the dresser 43. The steps 38a on the feed screw portion 38 and the support 39 function to provide relative motion between the members 31 and 36 when the shaft 37 is rotated.

The dresser-holding member 40 is located at the lower end of the swing arm 52. A holder 42 is secured to the dresserholding member 40. The holder 42 is keyed to the member 40 so that it is only capable of moving in an axial direction. A feed screw 41 and a knob 45 connected thereto function to adjust the position of the dresser 43. The feed screw is threaded into a dresserfixing shaft 44 so that rotation of the knob 45 causes the shaft 44 to move axially. The dresser 43 is connected to the shaft 44. The tip of the dresser 43 is attached to the arm 52 so that the axis of the dresser is at right angles to the axis of the grindstone 54 when the dresser 43 is midway between two circular peripheral faces of the grindstone 54.

The operation of the apparatus illustrated in FIGS. 1-4 is as follows. First, the cutting table 2 is moved in a direction toward the grindstone 54 by the amount the grindstone is to be dressed. This is accomplished by rotating the wheel 7. Next, a pressurized fluid from a source (not shown) is delivered to the right chamber 23R of the cylinder 23. This causes the piston 24 to slide from its original position toward the forward end (lower forward end after stroke adjustment). As the piston slides, the rack bar 22 connected thereto moves along with it. The teeth 22:: on the rack bar mesh with the pinion teeth 21a on the gear segment 21. The table 13b is thereby caused to rotate in a counterclockwise direction around the swing axis 13, as viewed in FIG. 1. Just prior to supplying the chamber 23R with fluid the left chamber 48L of the cylinder 48 is filled with pressurized fluid. The piston 49 associated with the cylinder 48 is thereby pushed to the right, as viewed in FIG. 1, which ultimately causes the table 31 to swing in a clockwise direction until the stop bolt A hits the stop B. In view of the pressure acting on the cylinder 48, the tables 25, 31 and 36 are integrally linked together. Thus, the swing of the table 13b causes the simultaneous swinging of the tables 25, 31 and 36. Thus, as the piston 24 is manipulated the swing arm 52 is caused to rotate in a counterclockwise direction, as viewed in FIG. 1, about the axis of rotation of the swing shaft 13. The dresser 43 makes an arc dressing of one of the circular peripheral faces of the grindstone by rotating around the swing axis 13 from the position I of FIG. to the position II of FIG. 5. The dog 24a associated with the piston 24 is adjusted so that the dog engages the cylinder 23 when the dresser 43 is positioned at location II of FIG. 5. Next, when the pressurized fluid is supplied to the right chamber 48R of the cylinder 48 the piston 49 slides from the original position toward the forward end (left forward end after stroke adjustment). During movement of the piston 49 the right chamber 23R of the cylinder 23 is supplied with pressurized fluid. When the piston 49 slides the rack bar 47 shifts in the same direction thereby causing the swing table 31 to swing around the axis of rotation of the body 29. The swing arm 52 moves with the table 31. The dresser 43 then dresses the other of the circular peripheral faces of the grindstone 54 with the axis of rotation of the body 29 serving as the rotational axis for the swing arm 52. When the dog 49a engages the cylinder 48 the dresser 43 is positioned as illustrated at position III in FIG. 5.

When the cylinders 48, 23 are operated in the opposite direction the dresser 43 performs a dressing operation on the periphery of the grindstone 54 in reverse direction to the above. Ultimately, the dresser 43 returns to its original position identified as I in FIG. 5.

FIG. 6 diagrammatically illustrates a convex arc dressing performed on each peripheral face of grindstone 54. In this case the center of the axis of rotation of the swing shaft 13 and the center of the axis of rotation of the swing body 29 may be shifted in a reverse relationship with respect to the grindstone 54 by adjusting the feed shafts l0 and 27. When a grindstone with different arc radii and different are centers lying on a line parallel to the axis of the grindstone is to be dressed on its peripheral faces, the stops A and C may be adjusted along with the dogs 24a and 49a as well as the feed shafts 10, 27 and 37.

Thus, according to the present invention the swing arm 52 holding the dresser 43 is connected to rotate about the axis of rotation of the swing shaft 13 and the axis of the swing body 29. Appropriate mechanisms are provided for swinging both the shaft 13 and the swing body 29. Also, mechanisms are provided for adjustably spacing the axes of shaft 13 and body 29 from one another. The swing body 29 slides in a direction parallel to the axis of the grindstone 54 while mechanisms are provided for shifting the swing arm 52 in a direction normal to the axis of the grindstone. Accordingly, it is a relatively simple operation to dress the periphery of a grindstone such as 54 which is composed of two convex arcs with the arc centers located inside the grindstone width. It is equally simple to dress the convex and concave peripheries of adjacent grindstones, or to dress peripheral grindstone arcuate faces having different radii.

I claim:

1. A double spherical dressing apparatus for dressing a grindstone of the type having two circular peripheral faces with different centers each lying on a line parallel to the axis of rotation of the grindstone comprising a framework,

a cutting table slidably mounted on the framework for movement normal to the axis of rotation of the grindstone,

motivating means for moving the cutting table relative to the grindstone,

a main assembly slidably mounted on the cutting table for movement parallel to the axis of rotation of the grindstone,

a swing shaft rotatably mounted within the main assembly,

first driving means for rotating the swing shaft,

a swing table pivotally mounted to the swing shaft,

a downwardly extending arm slidably mounted on the swing table for movement normal to the axis of rotation of the grindstone,

a dressing tool at the lower end of the arm, and

second driving means for rotating the swing table whereby the dressing tool may be selectively swung about each of the axes of the swing shaft and the swing table when the first and second driving means are operated, and the axis of the dressing tool and the axis of rotation of the grindstone being at right angles to each other when the dressing tool is midway between the two circular peripheral faces of the grindstone.

2. A double spherical dressing apparatus as in claim 1 wherein the swing table is slidably connected to the swing shaft for movement parallel to the axis of rotation of the grindstone.

3. A double spherical dressing apparatus as in claim 1 wherein the first driving means is connected to rotate the swing shaft and the swing table as a unit when the dressing tool tive to the main assembly and the amount of swing of the swing table relative to the swing shaft.

5. A double spherical dressing apparatus as in claim 4 including first adjustable stop means between the main assembly and the swing shaft for limiting relative movement thereof and second adjustable stop means between the swing shaft and the swing table for limiting relative movement thereof. 

1. A double spherical dressing apparatus for dressing a grindstone of the type having two circular peripheral faces with different centers each lying on a line parallel to the axis of rotation of the grindstone comprising a framework, a cutting table slidably mounted on the framework for movement normal to the axis of rotation of the grindstone, motivating means for moving the cutting table relative to the grindstone, a main assembly slidably mounted on the cutting table for movement parallel to the axis of rotation of the grindstone, a swing shaft rotatably mounted within the main assembly, first driving means for rotating the swing shaft, a swing table pivotally mounted to the swing shaft, a downwardly extending arm slidably mounted on the swing table for movement normal to the axis of rotation of the grindstone, a dressing tool at the lower end of the arm, and second driving means for rotating the swing table whereby the dressing tool may be selectively swung about each of the axes of the swing shaft and the swing table when the first and second driving means are operated, and the axis of the dressing tool and the axis of rotation of the grindstone being at right angles to each other when the dressing tool is midway between the two circular peripheral faces of the grindstone.
 2. A double spherical dressing apparatus as in claim 1 wherein the swing table is slidably connected to the swing shaft for movement parallel to the axis of rotation of the grindstone.
 3. A double spherical dressing apparatus as in claim 1 wherein the first driving means is connected to rotate the swing shaft and the swing table as a unit when the dressing tool is rotated about the axis of the swing shaft, and the second driving means is connected to rotate only the swing table when the tool is swung about the axis of the swing table.
 4. A double spherical dressing apparatus as in claim 3 wherein the first and second driving means include adjusting means for varying the amount of swing of the swing shaft relative to the main assembly and the amount of swing of the swing table relative to the swing shaft.
 5. A double spherical dressing apparatus as in claim 4 including first adjustable stop means between the main assembly and the swing shaft for limiting relative movement thereof and second adjustable stop means between the swing shaft and the swing table for limiting relative movement thereof. 